Electronic components can be damaged by exposure to electric fields such as EMI, RFI, and static electric fields. Various packaging materials have been developed to protect electronic components from these fields.
An EMI/RFI shielded two part container is disclosed in U.S. Pat. No. 4,609,104 to Kasper et al. The container comprises a sleeve having a continuous layer of a conductive metal on the inner side thereof and a transporter which slides into the sleeve and contains a continuous layer of a conductive metal on its inner surface. The transporter has at least one tab foldable outwardly to bring the metallic layer of the transporter into contact with the metallic layer of the sleeve as the transporter is slid into the sleeve.
U.S. Pat. No. 4,658,958 to McNulty et al. provides an optically transparent and flexible laminated article for packaging electronic components which provides EMI and RFI shielding and electrostatic dissipation. The article comprises a fibrous mat of woven or non-woven electrically conductive carbon fibers disposed between outer layers of polymeric material, generally low density polyethylene.
A static shielded shipping container is disclosed in U.S. Pat. No. 4,480,747 to Kazor et al. This container comprises two separable container portions, each coated on one side with a conductive layer. the portions engage so that the upper portion slides over the lower portion bringing the two conductive layers into electrical contact whereby the objects placed within the container are completely surrounded by a conductive cage. The conductive coating is exposed on the bottom surface of the assembled container to insure that the conductive cage is grounded to any conductive object on which the container is placed.
An electronically conductive container for grounding circuit boards and similar planar objects is disclosed in U.S. Pat. No. 4,308,953 to Cohen. The container comprises a container member, preferably formed from cardboard material, having an interior wall onto which electrically conductive holding panels having a plurality of slots therein are arranged to hold the planar objects placed in the container. The conductive coating may, for example, be carbon black or graphite impregnated paper. A portion of the exterior wall surface of the container member is electrically conductive, and electrically conductive means are provided for electrically connecting the holding panels to the exterior portion of the container member.
It has also been known to use montmorillonite clay to provide an electroconductive coating on paper to make a copy sheet for electrophotography as disclosed in U.S. Pat. No. 3,639,162 to Bixler.